A B757 Captain noted a difference between the TOTALIZER fuel and the FMC CALC fuel. Maintenance dismissed the report and released the aircraft for flight. The reporter later discovered that the engine low-pressure pump was replaced because of an out of tolerance fuel leak.

Narrative

During a series of fuel checks at reporting points during cruise. I observed a slowly increasing difference between actual fuel on the totalizer fuel (TOT) and the calculated fuel (CALC) on the FMC Program page 2. The TOT fuel was lower than the CALC fuel and the difference was gradually increasing until at top of descent TOT was 1400 LBS less than CALC fuel. Although there was about a 600 LBS imbalance between wing tanks (left was 600 LBS lower than right); this amount of imbalance was observed to have been there since prior to departing the gate and did not change in flight. When in radio range; we called maintenance on the radio and stated the nature of the problem and requested they meet us upon arrival. Several mechanics met the flight. One informed me that he observed a leak at the left engine low pressure fuel pump and also observed that the thrust reverser on the outboard side of the left engine seemed somewhat wet; although he could not say it was fuel. Because any fuel leaking from the engine after shutdown and with no fuel pumps on would not provide the best evidence of a fuel leak under pressure; the Mechanic informed me that they would run the engine and check it under pressure. As I was leaving the aircraft; the mechanics began preparing for the engine run by starting the APU. I did not remain during the engine run. In reviewing the maintenance record I am concerned about the verbiage in the sign off on my own write-up on the problem. The sign off indicated there were no faults in the fuel processor or FMC; that they observed the TOT was the same as CALC so no problem actually existed; implying the 'problem' was a figment of my imagination. This is offensive to me. We had the problem and I documented it. I suspected the indication might 'go away' after shutdown; which is why I specifically checked and documented the qualities at the gate 'before' we shut down. The numbers I recorded in the logbook were accurate and true. It concerns me to see the write-up of a Captain dismissed in such a manner as to impugn my integrity and essentially call me a liar.